This invention pertains to surgical systems and, more particularly, methods and apparatus for attaching tissue to bone. The invention has application in, for example, rotator cuff repair.
It is not uncommon for tendons and other soft tissues to tear or to detach from bone. Athletes, for example, often suffer xe2x80x9crotator cuffxe2x80x9d tears, in which the supraspinatus tendon separates from the humerus, causing pain and loss of ability to elevate and externally rotate the arm. Complete separation can occur if the should is subjected to gross trauma. Typically, however, the tear begs as a small lesion, especially, in older patients.
To repair a torn rotator cuff, surgeons must reattached the supraspinatus tendon to the humerus. Traditionally, this has been done by boring several holes obliquely through the greater tuberosity, that is, the bony structure on the outer side of the head of the humerus. Sutures are then passed through these holes, or transosseous tunnels, in order to secure the tendon.
Though use of such sutures to anchor the tendon have been referred to as the xe2x80x9cgold standard,xe2x80x9d it has been shown that the sutures migrate through the bone itself; particularly, along the upper edge of the openings that define the ends of transosseous tunnels on lateral cortex of the greater tuberosity. This is particularly pronounced in older patients, whose bone structures tend to be weaker and, therefore, less resistant to degradation under the force of the sutures. On prior art solution has been to augment the edges of the transosseous tunnels by affixing plate-like pieces; see, Gerber et al, xe2x80x9cMechanical Strength of Repairs of the Rotator Cuff,xe2x80x9d Journal of Bone Joint Surgery, v. 76, n. 3, p. 371-380 (May 1994). See France et al, xe2x80x9cBiomechanical Evaluation of Rotator Cuff Fixation Methods,xe2x80x9d The American Journal of Sports Medicine, v. 17, n. 2, pp. 176 et seq.
Drawbacks of plate-like augmentation of the greater tuberosity are the difficulties in positioning and affixing the plates. Though endoscopic surgery is generally preferred, use of augmentation plates necessitates that rotator cuff repair be performed by open surgery. Moreover, the plates must be affixed to the bone by surgical glues in order to avoid risk that they will migrate from the site in the event of suture breakage.
An object of this invention is to provide improved surgical systems and, more particularly, methods and apparatus for attaching tissue to bone.
Another object of this invention is to provide improved methods and apparatus for rotator cuff repair.
A related object of the invention is to provide improved methods for reinforcing the edges of transosseous tunnels against force of sutures.
The above objects are among those met by the invention, which provides in one aspect an improvement on a method for attaching soft tissue to bone by passing a suture through an opening in the bone, e.g., a transosseous tunnel, and affixing the soft tissue with the suture. The improvement, for preventing the suture from migrating through the bone at the end of the opening, includes placing a eyelet into an end of the bone opening and passing the suture through the eyelet, as well as through the opening in the bone, in order to affix the soft tissue with the suture.
In a related aspect, the invention provides a method as described above for use in attaching the spinatus tendon to the humerus bone by placing an eyelet into an end of a transosseous tunnel and passing the suture through the eyelet, as well as through the tunnel, in order to affix the tendon to the humerus.
Further aspects of the invention provides methods as described above, in which the eyelet is screwed, or fit by interference, into the bone opening. In still farther related aspects, the bone opening is expanded prior to placement of the eyelet.
In another aspect, the invention provides an apparatus for use in rotator cuff repair for reinforcing a transosseous tunnel to prevent migration of a suture through bone at the end of the tunnel. The apparatus comprises an eyelet arranged for placement within the end of the tunnel, or within an expanded hole formed at the end of the tunnel. The eyelet has a channel therethrough for passage of the suture and can include a flanged head to prevent the eyelet from being forced too far into the tunnel.
Related aspects of the invention provide an apparatus as described above in which the eyelet is threaded for screwing into bone on the inside of the wall of the hole or, alternatively, is arranged for interference fit with that inside wall.
Still another aspect of the invention provides an improvement on a method for attaching soft tissue to bone by passing a suture through an opening in the bone and affixing the soft tissue with the suture. The improvement, for reinforcing the bone opening, includes placing an expandable member into an end of the bone opening and inserting an insertion element into a channel that passes through the expandable member. A portion of the insertion element has an outer diameter greater than an inner diameter of at least a portion of the channel in the expandable member, so that insertion of the insertion element into the expandable member causes the expandable member to expand to obtain a pressure fit with the bone opening. The improvement further includes passing the suture through an channel of the insertion element, as well as through the opening in the bone, in order to affix the soft tissue with the suture.
Another aspect of the invention provides a method as described above in which the expandable member is substantially cylindrical and has an axial channel that extends between its proximal and distal ends. According to this embodiment, the insertion element is likewise elongate and has an axial channel extending between its proximal and distal ends.
In yet another aspect, the methods described above are adapted for rotator cuff repair. Accordingly, the step of placing the expandable member into the end of the bone opening comprises placing that member into the end of a transosseous tunnel in the humerus.
Yet another aspect of the invention provides methods as described above in which an emplacement element is used to place an expandable member into the end of the bone opening. In a related aspects, the emplacement element is frangibly attached to the expandable member such that application of force to the insertion element breaks the frangible attachment between those elements after that force has caused the insertion element to expand the expandable member.
Advantages of the invention include the ability to install the reinforcing eyelet via endoscopic surgery, as well as open surgery.
These and other aspects of the invention are evident in the drawings and in the description that follows.